Fast high power microwave components based on beam generated plasmas

Summary form only given. The NRL Agile Mirror program has demonstrated that a planar plasma can be produced quickly (over a few microseconds), efficiently and quietly (very little microwave noise added to the signal). Key to the success has been the discovery and exploitation of a new type of hollow cathode discharge which has been called the enhanced glow mode. So far rapid agility has not been demonstrated. However the capability of the plasma to act as a fast, high power microwave switch or phase shifter is another potential application for the technology. This paper investigates this possibility. The plasma as a phase shifter is evaluated, and so are various limiting factors such as attenuation, maximum power handling capacity (due to microwave breakdown and parametric instability), noise generation and reflection. Generally, the maximum power at X band is a few hundred Watts per cm/sup 2/, and at W band perhaps 100 times that much. However at W band, there is more attenuation in the plasma.